SAN FRANCISCO — On a quiet day for the Giants offense, the hardest hit Saturday came from Jarrett Parker crashing into the left-field fence.

As the crowd cheered the sensational leaping grab in the fourth inning, it soon became clear that something was horribly wrong: Parker grasped at his shoulder and crumpled to the ground in agony.

X-rays revealed a broken right clavicle. The Giants provided no timetable for Parker’s return, but it’s obvious it won’t be soon.

“He was pretty down,” Manager Bruce Bochy said after the Colorado Rockies breezed to a 5-0 victory at AT&T Park. “This kid was getting a chance, finally. It’s a shame. That was some kind of catch. I don’t know how he held onto the ball. … A bad break for him, a bad break for us.”

Bochy planned to huddle with general manager Bobby Evans and other Giants decision-makers to figure out how to replace Parker on the roster.

In the meantime, the Giants also had time to consider their tepid performance against Tyler Chatwood. The Rockies right-hander carried a perfect game into the sixth inning before polishing off a two-hitter.

The Giants offense consisted of a Chris Marrero singled in the sixth, a Joe Panik single in the seventh and a Denard Span walk in the ninth.

And that was it.

“The best stuff we’ve seen,” Bochy said of Chatwood. “He was pitching at 95 mph and bumping at 96-97, with a lot of life to it.”

It was the first time the Giants have been shutout since last Sept. 28 — when Chatwood was on the mound. He threw 8.0 innings in that game before turning things over to Boone Logan and Adam Ottavino.

Chatwood is now 4-1 with a 1.29 ERA over his last seven outings at AT&T Park. He needed only 105 pitches for his second career complete game, striking out four and walking one.

Marrero, who ended the perfect-game bid, spent the first five innings on the bench. “It looks easy when you watch from the dugout,” he said. “But once you get in that batter’s box, you actually see everything moving. He was really spotting hit pitches today.”

Giants starter Matt Moore was no match for Chatwood, wobbling through 5 2/3 innings. The left-hander surrendered 5 runs on 10 hits, including a solo home run to Nolan Arenado in the third. Moore said he was trying to get “too big” with some key pitches and wound up overthrowing the ball.

It could have been worse, but with two out and a runner aboard in the fourth, Parker chased down D.J. LeMahieu’s long drive with an all-out sprint into the left-field wall.

Parker’s body slammed shoulder-first into the space between the 2010 and 2012 championship flags painted onto the lightly padded fence. Parker snuffed the rally with his defensive gem but paid a terrible price.

“You feel for a guy like that,” Moore said. “It’s not like he made a careless mistake. He’s just going out and playing the game hard.”

Bochy said: “That’s how he plays. He’s an intense guy and he plays all out. … There’s no backing off, there’s no fear of the fence. Something has to give, and that was his clavicle.”

The Giants are 3-3 on this homestand with one more game remaining against the Rockies before hitting the road. Jeff Samardzija starts Sunday trying to salvage a rough April (0-2, 6.75 ERA).

— Giants prospect Christian Arroyo is off to a hot start at Triple-A. The 21-year-old infielder has a slash line of .467 / .500 / .667 over his first eight games for the River Cats. There are no plans on the horizon to promote Arroyo, but Bochy said the Giants are pleased with his progress.

“This kid is knocking on the door now,” Bochy said before the game. “If anything happens, we have somebody ready.”

— This marked the 70-year anniversary of the day Jackie Robinson broke baseball’s color barrier. As part of an annual tradition, all players wore Robinson’s jersey as a salute to No. 42. “It’s just a day when all of us have a chance to say thanks and honor this man,” Bochy said.